Many modern antenna applications require high bandwidth, dual polarization array antennas. Many of these applications also require low cross polarization between antenna elements. It is further desirable for the elements of an array antenna to have coincident phase centers for different polarizations to reduce the need for complicated polarization calibrations. Additionally, antenna designs should be relatively easy and low cost to manufacture. Due to size and weight constraints in some applications, it may also be desirable that antennas be lightweight and relatively low-profile.
As is known in the art, PCB-based dual polarized thumbtack antennas with coincident phase centers and a single RF port per element require an embedded power divider. At intercardinal scan and with high input power, the power divider circuit may dissipate a substantial amount of heat. Conventional thumbtack construction and interconnect provides a relatively inefficient thermal path for heat rejection. While quad-notch antennas remove the need for a power divider within the PCB eggcrate structure, these antennas requires multiple times the interconnect density. At higher frequencies packaging such a structure can become impractical.
Conventional wideband dual polarized radiators are known to have limitations in power handling. Prior attempts to address power issues include machining housings for individual boards to provide a thermal path, which requires considerable additional weight, complexity and cost. Other attempts to address power issues include using a quad notch antenna structure or an offset notch antenna structure. However, the quad notch structure requires many RF interconnects rendering it difficult to package a tight lattice. The offset notch antenna does not require the same level of thermal management but does not allow for coincident phase center dual polarized elements.